Nailing machine



Jan. 8 1924. 1,480,444

L. A. HOLMAN NAILING MACHINE Filed Dec. 6, 1919 s Sheets-Sheet 1 Wren/1 f a Z es/ne fl //a/maw y Jan. 8, 1924. 1,480,444 L. A. HOLMAN NAILING MACHINE 7 Filed Dec. 6, 1919 s Sheets-Sheet 3' knew/or A 65/13 6. Hal/nah F/ca. 6 I 5y Patented Jan. 8, 1924.

g LESLIE A. HOLMA1\T,'OF WALTHAMQMASSACHUSETTS! lvnxnrne MACHINE. i

I 'Appliication filed December G, 1919, Serial No; 343,018,]

T all whom it may concern Be it known that I, LESLIE A.'H0LMAN, a

citizen of the United States, and resident of the city of Waltham, in the State of Mas sachusetts and United Statesof America, have inventedcertain new and usefulImprovenients in N'allin Machines, of which the following is a ful clear, and exact do:

l be readily ascertained from'the following.

scfiption'. .1

This invention relates to improvements'in nailing machines and the primary objects of the invention are to secure great accuracy of nail feed and adequate support of the nail during driving, thereby avoiding bent or improperly driven nails. v 7

Various other objects and advantages will description. r

The device consists briefly of a frame carrying a reciprocating nailer head and a nail feeding device. The nailerhead has re= siliently connected thereto a nail holder to which nails are automatically supplied by the feeding device. A- clutch is provided be-f tween the nailer head and the source of power and is adapted to be operated automatically or manually. i

.In the drawingswhich illustrate the invention Fig. 1 isla front elevation of the machine.

Fig. 2 viewed from the right. V v Fig. 3 is a fragmentary side elevation viewed from the left.

Fig. 4 is a front elevation of the nail holder with the cover plate removed.

Fig. 5 is a vertical section of the complete nail holder on the line 5 5, Figure 4.

Fig. 6 is a longitudinal section of the nail feeding device. V f I Referring Inore particularly to the drawings, 11 designates the frame of the machine having at the top a bearing 12 in which the driving shaft13 isjournalled and at the front guiding fingers 14 and-15 which embrace the nailer head 16 and nail holder 17 respectively. The front end of the shaft is rigidly connected to a disc 18, which 7 reciprocates the nailer head 16 by'means of a connecting rod 19. The disc 18 isprovided with a rearwardly projecting flangeQOQ on which is mounted a brake band 21 retained in place by a ring 22 connected to thefiange and'hold against rotating with the disc by is a side elevation of the machine meansfof a tail 23," which is caught between thefra'me 11 and a bracket24 seguredfherer 1": 1

tol The brake band is provided with any suitable grip adjusting" means 25. 'A fly wheel 26 which also serves as a driving 'pulley is" revolub'ly mounted on the shaft in rear of thebearing 13.

This fly wheel has fixed thereto a ring '27 provided with end facingteeth 28, adapted to mesh with thesimilar teeth 29 of a sleeve 30 slidably but irrevolublymounted on the is held against rotation'on theshaftby a 1 pin 31 projecting radially from the shaft through a slot 32 in the sleeve. The sleeve 30 is reduced in diameter in its rearward" r portion 83 andcarries a'relatively revoluble sleeve 34. As will be notedin Figure 3, the

pin 31 iss'plit horizontally so asto leave a flat surface 35 projecting radially from the, shaft] The depthof this'split need not bev greater than the. depth of the shoulder be-Q tween the toothed and reduced parts of the sleeve 30. The sleeve 34 is provided on its forward end with a cam or ratchet tooth 36 adapted to co-operate with the'pin 31; This 7 sleeve 34 is provided with'an operating 11ever 37 towhichany suitable ope-rating memher 38 may be connected. The sleeve 3 1 is held against sliding rearwardly 01f the sleeve 30 by an adjusting nut 30*, having a rearwardly extending threaded :portion carrying'a cap'39 which covers the extremity of the shaft 13. In rear of the sleeve 30 a collar 4:0 'is adjustably mounted on. the

shaft 13, and a spring a1 is provided in compression between the collar and the rear end of the sleeve and operates :to urge the sleeve forwardly and into engagement with the ring 27. W

' The nailer head 16 is merely abar of metal sliding between the guides '14 and maintained by a cappl'ate 42. This head is provided with a longitudinal bore'48to re-i' ceivethenail driver 445,. which is adjustably mounted therein by means of a set screw 14 Thenail holder 17, whichfis located below the nailer head, is resiliently connected to the nailer head by means of a yoke 45 and springs 46 mounted on guides 47, rigidly connected 'to the yoke. 15 and slidable in yoke 4:8 secured to the bottom'of thenailer head. Adjustingnuts49 on the guide" rods 47 regulate the distance between the nail or back 51 and a cover'or front plate-'52.

The yoke 45 is connected to the body 51 by means of a screw 53 and carries a. dowel pin 54 to hold the lowerend .ofthe cover.52, which is attached atits. upper end to the back by screws 55. The upper part of the body 51 projects farther forward than the remainder thereof and is provided with a groove 56 for the nail drivere l. Below the grooved upper portion of thebody are a pairof nail holding fingers 57 pivotally mounted at their upper. ends to the front surface of the body. The upper portions of these fingers are spaced apart sufficiently to give clear passage for the nail driver, but the lower partsare normally in contact and are provided .on their contacting surfaces.

with grooves 58, which unite to form a nail passage. 7 so reduced in size that when the fingers are together the united groove ends form merely ,A nail passage-60 isprovided inthebody leading fromthe rear surface thereof at the top through to the front surface at a point slightly above thecut-away portion 59, and preferably inclined so that its aXis approximately strikes the upper endof the nail grooves, 58. The lower ends of the fingers are thickened on their front surfaces from their tips upwardly to a point, above the upper ends of the grooves 58, and this thickened portion serves to provide guard plates 61, which meet to close the space between the fingers for. a short distance above the grooves 58, sothat nail coming downthe passage 60 and overshooting the grooves'58 will strike the plates 61 and be deflected into proper position. The cuttingaway of the lower portion of the body 51 and the rearward extension of the. fingers thereinto effectually closes the crackbetweenthe fi'nany suitable manner to urge the fingers to-- ward one another. A stop pin 63 is provided for each finger and is positioned to prevent the finger swinging past the axis ofthe nail driver. The front plate 52 is pro- The lower end of this passage is,

vided'with an opening 6a through which the feed ofnails and the operation of the fingers and driver may be observed. In order that a shorter or longer nail driver may be substituted without the delayof removing thecap plates 50 and 52, the plate 52 is provided with a removable portion 65 lo cated in front of the driver slot 56.

The nail feeding device comprises an 0s, magazine 66 discharging to a magazine may be arranged to serve one or more chutes, for the reason hereafter'explained; The nail feeding device, to which the chutes deliver, comprises essentially a screw or worm 71and a plate '72, against or adjacent to which the worm operates. The screw is preferably provided with a square thread equal to or slightly shallower than the diameter of the nail to be fed. In order to permit changes in the size of nails used,

the screw is provided with a, tapered shank- 7 3, which enters a hollow driving shaft 74: and is secured by a pin or the like 75. The

shaft 7& is journalled in a bracket bearing 76 secured to the frame 11, and carries revolubly mounted thereon apinion 77 and rig with the pinion by means of a spring 80, which may, however, be swung to one side to permit removal of the pin and access to the bore of the shaft 7 L for. the purpose of driving out the screw 71. The counterplate 7 2, in conjunction with which the feed screw operates, curves gradually at its lower edge into an inclined trough 81 extending between the inner end of the screw and the upper end of the nail passage 60. The feed screw is drivenby, a chain 82 from a shaft 83. This shaft also operates as the timing shaft and controls the operation of the nail driver when the machine isoperating automatically. If the machine is operated at irregular intervals, suitable connection must be'established between this shaft or the feed crew and the shaft 13, in order to ensure the operation of the feeding device after each nailing operation. Forthcpurpose-of automatic operation, a cam 84 may be provided on the shaft 83 and arranged to operate the connecting link 38 once per revo lution.

Then the work to be nailed is of a nature which can be brought to the nailing machine at exactly regular intervals by means of a conveyor 85, the operation will be entirely automatic and the timing shaft 83 will be set in proper speed relation withthe conveyor toproduce an operation of the nailing machine at stated intervals during f the] movementofithe conveyor. When a conveyor is'u'sed, it is preferable to, prov de the same with apertures 86, through whichthe anvil 87 of the nailing'ma-chine may pro-- ject, these apertures being slightly longer than the anvil. An adjustable stop 88'may be provided in the path of-tthe yoke .45.

The operationof the devi'ceiis extremely simple. Assuming the machine to be in proper working adjustment, the parts will be all in the positions shown, except that the cam 36 will be in engagement with the pin 31 holding the sleeve teeth .29 out of mesh with the ring teeth 28. The, work to be nailed is placed on the anvil and the lever 37 depressed to revolve the sleeve. 34:. and

move its cam tooth 36 past the pin 31..

Owing to the splitting or flattening of the pin, this disengagement will be abrupt, as will be readily seen in Figure 3 andrwhen effected will release the sleeve 30, so that the spring 41 willithrow it against the ring 27' carried by the revolving fly wheel 26, so that the teeth mesh and the shaft 13 is revolved with the fly wheel. ever, held against revolution by the operating link 38 or other suitable means. :The connecting rod drives thenailer head 16 downwardly andthis movement is communicated through the springs 46 to the yoke i5 and nail holder, so that the nail'holder 1S moved downwardly into contact with the movement, of the nail holder is stopped by engagement with the work, the nailer head continues its downward -movement coma pressing the springs 46 and thus putting considerable pressure on the .work to hold it securely in place on the anvil orif it is of a soft nature'to compact it suitably for nailing. The continued downward move ment of "the nailer head forces the nail driver 4% down between the fingers 57 and into contact with the nail head, which is forcedbetweenand separates the fingers and is finally driven down fully into the work. It will be seen that the nail point is in contact with the work before the driver touches the nail and'also that if a proper length of nail isused the point of the nail will be set in'the work,"while itis still held by the fingers, and before thefingers have been forced apart to release the nail. Obviously under these conditions the'nail'point The sleeve 34 is, how-" vertically from their heads.

and'magazine perform a certamamount of. selection, so that verybadly deformed nailsthis portionof the groove.

bent, finned, flattened or over-size, they will be a tight fit between the screw and plate T2,

- so that the. 'movementof the screw will gradually raise-them until they fall out over 7 cannot slip and the nail be driven on a slant orbent in thedriving. .This'comple'testhe.

first half revolution of the shaft. 'During the second half revolution, the nailer head rises to itsproper distance above the nail holder, due tojthe compression of the springs 46, before the work is released. The nail holder is raised during the finalpart ofthe upward .movement and as itqiscoming to rest in its uppermost position a nail is dropped by the feed screw-71' into the trough- 81 and is thereby conducted into the pasgrooves 58 of the closed fingers. During the final part of the upward movement, the cam 36 is engaged by the pin 31 and the sleeve 34;

sage 60 through which it falls into the I is thus forced rearwardly and carrieswith it the sleeve 30,'so that on the completion of the revolution theteeth 28 and 29 draw out of mesh and revolution ofi-the shaft revolutionof the shaft. Owing to the fact that the flywheel is the .driving, element','it

will be understood'that there isvery little momentum in the shaft which must be ab-E sorbed before stoppage can be eflected.

stops.v Immediately the. driving :force' is taken ofi",.the drag of the brake 21 stops. I

Such momentum as there is is offset bythe fact that all theqmovin'g parts'ofthe ma chine are coming up to the; dead centre.

The nail magazine66 may be, connected with any suitable part'of the machine to oscillate.

or jog the same, for the purpose of keeping the nails in motion,;so thatthey work into -thefoutlet slots of themagazine and intothe chutes67down which they slide, hanging never reach the screw. Properly speaking,

the chuteshouldbe full of nails between the The feedchute I feed screw and the magazine. As the screw" is revolved in -the direction ofthe' arrow,

Figure 1, that" is upwardly on the sideadjacent the platef72, a turn in the groove thereof comes opposite the end of the chute.

and a nail slips into the screw groove filling the top of the screw. If the nails are under- If the nails'are size or headless, lthey will fall through the 4 screw. As the 'screwcont-inues to revolve,

the nails are :carried laterally toward the centre line of the machine. "The. purpose of providing two or more chutes'leading from themagazine is to ensurethe placing of a nail in each turn of the screw groove, since if one turn was empty there would be no 'nailto feed after one of the operations. If, for any reason, the screw should fail to receive a nail from the first chute or to recelve an lmperfect nail and re ectsame, the

empty space in the screw will befilled when it passes the second orany' subsequent chute; The presence of nails in the screw groove fills the groove opposite the chute endan'd prevents the entrance of further nails;

These nails in the screw in combination with the thread of the screw serve as a closure or gate at the-bottom of the second chuteand operate to hold nails inthe chute until a vacant turn or" the groove comes opposite the chute. In a great many instancesit will be sufficient to have a single chute leading from the magazine-and second chute not connected witlrthe magazine which may be filled by hand with per'fect'nails. The

revolution of the screw carries the nails laterally until the end of thescrew is reached and there is no'further transporting means, so that the nails are released and slide point firstdown thetrouglr 81. This enables the adjustment between the screw and counter plate'72 to bequite-fine, so that a very accurate selection of nails will result. Obviously, the proper speed relationbetween the shaft 13 and feed screw is 121, but this relation may be obtained satisfactorily with a screw revolving continuously, for example, at ten revolutions per minute and a shaft o'p'erating'intermittently at any.

greater number of revolutions per minute.

When the wor: to be nailed is brought to the machine on a conveyor 85, the downward movement of the yoke d5 presses'the" work down to the anvil, forcing the chain to-sa'g down in so doing. If the openings 86 of the chain are of sufficient size, the chain will.

continue to move but the" work will be held fast to the anvil during-the nailing operation. This arrangement" further ensures against crookedly driven nails.

The machine has a number of advantages which will be readily appreciated by those skilled in the use of nailingmachinesj The device adapts itself automatically to work of varying thickness and holds the work secure ly on'the anvil during the nailingoperation; If any considerable or permanent change in the thickness of the work is encountered;

the only adjustment required is to raise or. lower the nail holder by meansof the nuts 49"and to adjust the driver 44, When a' change is made .in'the length of the nail used,=the only adjustmentsrequired are pos sibly a change of holding fingers andthe adjustment of the driver 44;. While it" is preferable to have substantially the whole length of the nail held by the fingers: so as to absolutely centre the nail'under the driver, it is obvious that as much as 25% of the length of the nail may beabove the ends of the grooves 58 without danger of crooked driving. Owing to the fact that the point of the nail is brought right to the workbefore nailingconimences, the machine will drive the shortest nails as accurately as the awn-e longest" within its capacity. Sinking nail heads into 'the workand clinching the nails is merely aquestionof selecting the proper length of'n'ail and adjusting the driverl tz The provision ofa' limit stop 88 for the downwardmovenient of the holder serves to check its movement if no work should happenv'to beplaced' under it and cause the driver to advance far'enough to separate the fingers andall-ow the nail to drop, thus emptying the holdenready for the reception of a fresh" nail and so preventing clogging;

' liedescending "nail holder, which clamps the work to the anvil, eliminates movement of the work if i'ed bya conveyor during the nailing operation and so avoids improperly driven nails.v The nail feed is of the SlHl. plest possible character and will feed nails with: absolute regularity, so that there will never be an empty holder when the nailer descends. The releasable connection between the drive sprocket and feed screw enables accurate adjustment ofgthe nail feed and also permits the operator to run the machine for enamin'ation without feeding nails, and also to feed nails-without running the machine when settingthe machine up. The easily removable feed screw enables the machine to be readily changed to accommodate a nail holder positioned below the driver, a

yoke on the nail holder, guide rods rigidly connected to the ends of said yoke having slidable engagement with the nail driver, springs in compression between the yoke and driver, and adjustable stops on the guide rods limiting the separation of the driver and holder.

2. In a nailing machine, a nail driver, a nail holder, a nail feed screw, a timing shaft, drivingconnection between said timin'gshaft and the screw, a driving shaft for the nail driver, a continuously revolving pulley, a clutch adapted to connect and dis connect the pulley anddriver shaft. and operativeconnection between said clutch and the timing shaft; I

3. A device according to claim 2,, in

which the clutch is arranged to automati ca'lly disconnect the pulley and driver shaft on the completion of one revolution of the shaft; and in which-the operative connection includes a cam on the timing shaft and a link connecting said cam and clutch, the cam being arranged to operate the clutch once for each revolution of the feed screw.

4. The combination with a work conveyor of a nailing machine including nail holding and driving means on one side of the conveyor and an anvil on the opposite side of the conveyor, said nail holder being arranged to hold the work on the anvil durin nailing independently of the movement 0 the conveyor.

V 5. A device according to claim 4:, in which the conveyor is apertured at each work supporting point for the passage of the anvil V and normally supports the work above the contact with the anvil through apertures.

. In witness whereof, I have hereuntoset 2.0

in hand.

y LESLIE ,A. HOLMAN. 

